|
|
||||||||
1 Division of Biology, California Institute of Technology, Pasadena, California 91109
1. Artificially activated non-nucleate fragments and whole eggs of the sea urchins Strongylocentrotus purpuratus and Lytechinus pictus have been compared with regard to their ability to incorporate C14-labeled amino acid into protein. Each of the 20 "coded" amino acids has been tested, the tests being done in groups of ten. In both species non-nucleate fragments closely resemble whole eggs with regard to the pattern of incorporation of the sets of ten amino acids. Also there is similarity in the absolute incorporation values when the comparisons are made within individual experiments in which variation in size of the endogenous amino acid pool is not a factor.
2. The similarity in amino acid (valine) incorporation is maintained during the first six hours after activation. The values are similar to those for fertilized eggs, as earlier studies had also shown. Further, following the initial great rise shortly after fertilization, or artificial activation, the rate of incorporation remains relatively constant during this period.
3. The results provide additional evidence that the activation of protein synthesis upon fertilization does not depend upon production of mRNA by the nucleus. Further they show that the activated non-nucleate fragment and the whole egg do not differ appreciably in the kinds of proteins they synthesize during early development, that the corresponding mRNA's are all, or mostly all present in the unfertilized egg, and that most or all of these become "unmasked" soon after fertilization or artificial activation.
This article has been cited by other articles:
![]() |
C. N. Graves and J. D. Biggers Carbon Dioxide Fixation by Mouse Embryos prior to Implantation Science, March 13, 1970; 167(3924): 1506 - 1508. [Abstract] [PDF] |
||||
![]() |
A. C. Clement and A. Tyler Protein-Synthesizing Activity of the Anucleate Polar Lobe of the Mud Snail Ilyanassa obsoleta Science, December 15, 1967; 158(3807): 1457 - 1458. [Abstract] [PDF] |
||||
![]() |
W. Auclair and B. W. Siegel Cilia Regeneration in the Sea Urchin Embryo: Evidence for a Pool of Ciliary Proteins Science, November 18, 1966; 154(3751): 913 - 915. [Abstract] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |